Electronic cigarette
An electronic cigarette, also known as e-cigarette among other names, is a handheld battery-powered vaporizer that simulates smoking and provides some of the behavioral aspects of smoking, including the hand-to-mouth action of smoking, but without burning tobacco.2 Using an e-cigarette is known as "vaping" and the user is referred to as a "vaper."3 Instead of cigarette smoke, the user inhales an aerosol, commonly called vapor.4 E-cigarettes typically have a heating element that atomizes a liquid solutioncalled e-liquid.5 E-cigarettes are automatically activated by taking a puff;6 others turn on manually by pressing a button.3 Some e-cigarettes look like traditional cigarettes,7 but they come in many variations.3 Most versions are reusable, though some are disposable.8 There are first-generation,9 second-generation,10 third-generation,11 and fourth-generation devices.12 There are also pod mod devices that use nicotine in the form of a protonated nicotine, rather than free-base nicotine found in earlier generations.13 E-liquids usually contain propylene glycol, glycerin, nicotine, flavorings, additives, and differing amounts of contaminants.14 E-liquids are also sold without propylene glycol,15 nicotine,16 or flavors.17 The benefits and the health risks of e-cigarettes are uncertain.181920 There is tentative evidence they may help people quit smoking,21 although they have not been proven to be more effective than smoking cessation medicine.22 There is concern with the possibility that non-smokers and children may start nicotine use with e-cigarettes at a rate higher than anticipated than if they were never created.23 Following the possibility of nicotine addiction from e-cigarette use, there is concern children may start smoking cigarettes.23 Youth who use e-cigarettes are more likely to go on to smoke cigarettes.2425 Their part in tobacco harm reduction is unclear,26 while another review found they appear to have the potential to lower tobacco-related death and disease.27 Regulated US Food and Drug Administration (US FDA) nicotine replacement products may be safer than e-cigarettes,26 but e-cigarettes are generally seen as safer than combusted tobacco products.12930 The risk of early death is anticipated to be similar to that of smokeless tobacco.31 The long-term effects of e-cigarette use are unknown.323133 The risk from serious adverse events was reported in 2016 to be low.34 Less serious adverse effects include abdominal pain, headache, blurry vision,35 throat and mouth irritation, vomiting, nausea, and coughing.36 Nicotine itself is associated with some health harms.37 In 2019 and 2020, an outbreak of severe lung illness throughout the US was linked to vaping.38 E-cigarettes create vapor made of fine and ultrafine particles of particulate matter,36 which have been found to contain propylene glycol, glycerin, nicotine, flavors, small amounts of toxicants,36 carcinogens,39 and heavy metals, as well as metal nanoparticles, and other substances.36 Its exact composition varies across and within manufacturers, and depends on the contents of the liquid, the physical and electrical design of the device, and user behavior, among other factors.24 E-cigarette vapor potentially contains harmful chemicals not found in tobacco smoke.40 E-cigarette vapor contains fewer toxic chemicals,36 and lower concentrations of potential toxic chemicals than cigarette smoke.41 The vapor is probably much less harmful to users and bystanders than cigarette smoke,39 although concern exists that the exhaled vapor may be inhaled by non-users, particularly indoors.42 Since their entrance to the market in 2003,9 global use has risen exponentially.42 In a 2014 survey, about 13% of American high school students reported using them at least once in the previous month,43 and in 2015 around 10% of American adults were users.44 In the UK, users have increased from 700,000 in 2012 to 2.6 million in 2015.45 About 60% of UK users are smokers and about 40% are ex-smokers, while use among never-smokers in the UK is negligible.45 Most still use traditional cigarettes, raising concern that dual use may "delay or deter quitting".36 Most peoples' reason for using e-cigarettes involve trying to quit smoking, though a large proportion use them recreationally.6 It is commonly stated that the modern e-cigarette was invented in 2003 by Chinese pharmacist Hon Lik, but tobacco companies had been developing nicotine aerosol generation devices since as early as 1963.46 As of 2018, 95% of e-cigarettes were made in China.13 Because of overlap with tobacco laws and medical drug policies, e-cigarette legislation is being debated in many countries.47 The revised EU Tobacco Products Directive came into effect in May 2016, providing stricter regulations for e-cigarettes.48 As of August 2016, the US FDA extended its regulatory power to include e-cigarettes.49 Large tobacco companies have greatly increased their marketing efforts.26 As of 2014, there were 466 brands of e-cigarettes,50 with global sales of around $7 billion.